1. Field of the Invention
The present invention relates to printing and more specifically to printing image files obtained from medical diagnostic imaging systems.
2. Description of the Prior Art
The various modalities of medical diagnostic imaging systems, such as X-ray machines, ultrasound machines, CTs and MRIs, include one or more detectors for detecting image information produced by the interaction of the modality with the patient. These detectors typically include convertors for converting analog signals received thereby into digital signals that can be processed by a digital computer into an image file representative of the portion of the patient being imaged. The image files can be processed by the digital computer of the imaging system to produce on a monitor, such as a CRT, a visually perceptive image of the body part imaged by the imaging system. More specifically, the digital computer processes the digital signals from the detector into, among other things, luminescence values associated with each pixel of the image displayed on the monitor. Each pixel may also have associated therewith color and hue information.
It is common for an imaging system to process the received signals into a high resolution image which is provided to the monitor, preferably a high definition monitor which is capable of reproducing the high resolution image. In order to process these high resolution images, each pixel of the high resolution image may have associated therewith a luminescence value having 12 to 16 bits of resolution. The ability of the monitor to produce luminescence values having between 12 and 16 bits of resolution permits the imaging system to produce a high definition picture of the imaged portion of the patient.
While such high definition pictures are desirable, it is often desirable to produce hard copies of the imaged portion of the patient. In this respect, it is still common practice for X-ray machines to produce images on film based media. Limitations of film based media, however, include the use of hazardous chemicals for developing and the cost of replication, storage and retrieval of film based media. Hard copies of imaged portions of the patient may also be produced by providing image files to a printer having the same resolution as the luminescence values of the image file. Limitations of such a printer, however, is its cost and its relatively low availability with respect to more commonly available printers having lower resolution. While it is desirable to produce hard copies of diagnostic images from image files utilizing commonly available printers, the resolution of these printers for each luminescence value is typically limited to 8 bits. Hence, detail from the actual image is lost thereby limiting the usefulness of such hard copy images.
It is an object of the present invention to provide a printer which adaptively adjusts the scaling of its printer luminescence values to the luminescence values of a histogram containing one or more groups of image luminescence values containing the most diagnostically useful image information. It is an object of the present invention to provide a method for adaptively converting the scaling of printer luminescence values to image luminescence values containing more diagnostically useful image information.